Mouse cursor changes to 'resize' on inner widgets

michalos

Hi,
I have a GUI, that has a tab widget.
On every tab there is a tree view and a editor widget.
Editor is shown only when I hover over an item, in the tree view.

Sometimes when I hover over the tree views empty space, or editors push buttons, the mouse cursor changes from the normal arrow, to the horizontal resize arrows (horizontal line with an arrow on each side).
It happens only from time to time.

My main window is frameless (Qt::FramelessWindowHint) and I do the resizing manualy. I've set breakpoints on the code, where I change the mouse coursor to the resize one, but It looks like it's not related to my code (doesn't execute this code when the problem occurs).

I can supply all the code you need, but its a complex application and I'm not sure where to look.

Could someone give me some hints on where to look for the cause of the problem?

One dependency I found is, that when I do something else in a seperate program, and then hover the mouse over the app.

What helps is to switch vews (from one tab in a tab widget, to another, and then back)

mrjj

Hi
Can it be a hidden splitter ?

If you // out any use of setCursor, does it still happen?

michalos

@mrjj thank you for your answer.

I do not have any splitters in those widgets.
I did not try to comment out the setCursor, but I did place a breakpoint on the code, where I change the cursor to a resize cursor.

I will try to comment out setCursor.

mrjj

@michalos

I cant think of any other widgets (besides as a window) that would use the
resize cursor. alt text

michalos

@mrjj said in Mouse cursor changes to 'resize' on inner widgets:

nt think of any other widgets (besides as a window) that

I will do some more testing, because the problem only happens form time to time, but it seems, that code from a class I borowed from github seems to be the problem:

void FrameLess::updateCursorShape(const QPoint &pos) {
    if (_parent->isFullScreen() || _parent->isMaximized()) {
        if (_cursorchanged) {
            _parent->unsetCursor();
        }
        return;
    }
    if (!_leftButtonPressed) {
        calculateCursorPosition(pos, _parent->frameGeometry(), _mouseMove);
        _cursorchanged = true;
        if (_mouseMove.testFlag(Edge::Top) || _mouseMove.testFlag(Edge::Bottom)) {
            _parent->setCursor(Qt::SizeVerCursor);
        } else if (_mouseMove.testFlag(Edge::Left) || _mouseMove.testFlag(Edge::Right)) {
            _parent->setCursor(Qt::SizeHorCursor);
        } else if (_mouseMove.testFlag(Edge::TopLeft) || _mouseMove.testFlag(Edge::BottomRight)) {
            _parent->setCursor(Qt::SizeFDiagCursor);
        } else if (_mouseMove.testFlag(Edge::TopRight) || _mouseMove.testFlag(Edge::BottomLeft)) {
            _parent->setCursor(Qt::SizeBDiagCursor);
        } else if (_cursorchanged) {
            _parent->unsetCursor();
            _cursorchanged = false;
        }
    }
}

When I comment out the _parent->setCursor() the problem stopped.

Any idea why the coursor only locks it selve on the Qt::SizeHorCursor?


void FrameLess::mouseHover(QHoverEvent *e) {
    updateCursorShape(_parent->mapToGlobal(e->pos()));
}

void FrameLess::mouseLeave(QEvent *e) {
    if (!_leftButtonPressed) {
        _parent->unsetCursor();
    }
}
void FrameLess::mouseMove(QMouseEvent *e) {
    if (_leftButtonPressed) {
        if (_dragStart) {
            _parent->move(_parent->frameGeometry().topLeft() + (e->pos() - _dragPos));
        }

        if (!_mousePress.testFlag(Edge::None)) {
            int left = _rubberband->frameGeometry().left();
            int top = _rubberband->frameGeometry().top();
            int right = _rubberband->frameGeometry().right();
            int bottom = _rubberband->frameGeometry().bottom();
            switch (_mousePress) {
            case Edge::Top:
                top = e->globalPos().y();
                break;
            case Edge::Bottom:
                bottom = e->globalPos().y();
                break;
            case Edge::Left:
                left = e->globalPos().x();
                break;
            case Edge::Right:
                right = e->globalPos().x();
                break;
            case Edge::TopLeft:
                top = e->globalPos().y();
                left = e->globalPos().x();
                break;
            case Edge::TopRight:
                right = e->globalPos().x();
                top = e->globalPos().y();
                break;
            case Edge::BottomLeft:
                bottom = e->globalPos().y();
                left = e->globalPos().x();
                break;
            case Edge::BottomRight:
                bottom = e->globalPos().y();
                right = e->globalPos().x();
                break;
            }
            QRect newRect(QPoint(left, top), QPoint(right, bottom));
            if (newRect.width() < _parent->minimumWidth()) {
                left = _parent->frameGeometry().x();
            } else if (newRect.height() < _parent->minimumHeight()) {
                top = _parent->frameGeometry().y();
            }
            _parent->setGeometry(QRect(QPoint(left, top), QPoint(right, bottom)));
            _rubberband->setGeometry(QRect(QPoint(left, top), QPoint(right, bottom)));
        }
    } else {
        updateCursorShape(e->globalPos());
    }
}

mrjj

Hi
Well it sounds like sometimes, you experience a situation that is not properly
covered by the logic and maybe _cursorchanged or _leftButtonPressed is not
in expected state and the cursor is not reset.

This one
https://github.com/dfct/TrueFramelessWindow `?

michalos

@mrjj

I will debug the code some more and try to find the conditions this happens.

as to the code, it's not the TrueFramelessWindow. I've tried to find it, but it's as if someone removed it..

mrjj

@michalos
super.
I would insert
qDebug() in a few places so I could run the app with no break points and still see what is going on.

michalos

Hi again.
It took me awhile to check this code thoroughly, because of other projects, but I've checked it now.
The results are strange:
When I comment out the line responsible for mouse cursor change, the error does not occur.
When I enable the code, but add qDebug info one line above (before code execution), then the error occurs, but I don't get any debug info about it.
Any ideas on how is this possible?

I wanted to take a screenshot of this error, but the mose is not visible on the screenshot.

and here's the whole code, as it is right now:


#include <QDateTime>
#include <QDebug>

FrameLess::FrameLess(QWidget *parent) :
    QObject(parent),
    _parent(parent),
    _cursorchanged(false),
    _leftButtonPressed(false),
    _borderWidth(3),
    _dragPos(QPoint())
{
    _parent->setMouseTracking(true);
    _parent->setWindowFlags(Qt::FramelessWindowHint);
    _parent->setAttribute(Qt::WA_Hover);
    _parent->installEventFilter(this);
    _rubberband = new QRubberBand(QRubberBand::Rectangle, parent);
}

bool FrameLess::eventFilter(QObject *o, QEvent*e) {
    if (e->type() == QEvent::MouseMove ||
        e->type() == QEvent::HoverMove ||
        e->type() == QEvent::Leave ||
        e->type() == QEvent::MouseButtonPress ||
        e->type() == QEvent::MouseButtonRelease) {

        switch (e->type()) {
        case QEvent::MouseMove:
            qDebug() << QDateTime::currentDateTime() << "FrameLess::eventFilter : QEvent::MouseMove";
            mouseMove(static_cast<QMouseEvent*>(e));
            return true;
            break;
        case QEvent::HoverMove:
            qDebug() << QDateTime::currentDateTime() << "FrameLess::eventFilter : QEvent::HoverMove";
            mouseHover(static_cast<QHoverEvent*>(e));
            return true;
            break;
        case QEvent::Leave:
            qDebug() << QDateTime::currentDateTime() << "FrameLess::eventFilter : QEvent::Leave";
            mouseLeave(e);
            return true;
            break;
        case QEvent::MouseButtonPress:
            qDebug() << QDateTime::currentDateTime() << "FrameLess::eventFilter : QEvent::MouseButtonPress";
            mousePress(static_cast<QMouseEvent*>(e));
            return true;
            break;
        case QEvent::MouseButtonRelease:
            qDebug() << QDateTime::currentDateTime() << "FrameLess::eventFilter : QEvent::MouseButtonRelease";
            mouseRealese(static_cast<QMouseEvent*>(e));
            return true;
            break;
        default:
            qDebug() << QDateTime::currentDateTime() << "FrameLess::eventFilter : default:";
            mouseRealese(static_cast<QMouseEvent*>(e));  //default was just the return false; - I've added the mouseRelalese();
            return false;
            break;
        }
    } else {
        return _parent->eventFilter(o, e);
    }
}

void FrameLess::mouseHover(QHoverEvent *e) {
    updateCursorShape(_parent->mapToGlobal(e->pos()));
}

void FrameLess::mouseLeave(QEvent *e) {
    if (!_leftButtonPressed) {
        _parent->unsetCursor();
    }
}

void FrameLess::mousePress(QMouseEvent *e) {
    if (e->button() & Qt::LeftButton) {
        _leftButtonPressed = true;
        calculateCursorPosition(e->globalPos(), _parent->frameGeometry(), _mousePress);
        if (!_mousePress.testFlag(Edge::None)) {
            _rubberband->setGeometry(_parent->frameGeometry());
        }
        if (_parent->rect().marginsRemoved(QMargins(borderWidth(),borderWidth(),borderWidth(),borderWidth())).contains(e->pos())) {
            _dragStart = true;
            _dragPos = e->pos();
        }
    }
}

void FrameLess::mouseRealese(QMouseEvent *e) {
//    if (e->button() & Qt::LeftButton) {  //i've commented it
        _leftButtonPressed = false;
        _dragStart = false;
//    }
}

void FrameLess::mouseMove(QMouseEvent *e) {
    if (_leftButtonPressed) {
        if (_dragStart) {
            _parent->move(_parent->frameGeometry().topLeft() + (e->pos() - _dragPos));
        }

        if (!_mousePress.testFlag(Edge::None)) {
            int left = _rubberband->frameGeometry().left();
            int top = _rubberband->frameGeometry().top();
            int right = _rubberband->frameGeometry().right();
            int bottom = _rubberband->frameGeometry().bottom();
            switch (_mousePress) {
            case Edge::Top:
                top = e->globalPos().y();
                break;
            case Edge::Bottom:
                bottom = e->globalPos().y();
                break;
            case Edge::Left:
                left = e->globalPos().x();
                break;
            case Edge::Right:
                right = e->globalPos().x();
                break;
            case Edge::TopLeft:
                top = e->globalPos().y();
                left = e->globalPos().x();
                break;
            case Edge::TopRight:
                right = e->globalPos().x();
                top = e->globalPos().y();
                break;
            case Edge::BottomLeft:
                bottom = e->globalPos().y();
                left = e->globalPos().x();
                break;
            case Edge::BottomRight:
                bottom = e->globalPos().y();
                right = e->globalPos().x();
                break;
            }
            QRect newRect(QPoint(left, top), QPoint(right, bottom));
            if (newRect.width() < _parent->minimumWidth()) {
                left = _parent->frameGeometry().x();
            } else if (newRect.height() < _parent->minimumHeight()) {
                top = _parent->frameGeometry().y();
            }
            _parent->setGeometry(QRect(QPoint(left, top), QPoint(right, bottom)));
            _rubberband->setGeometry(QRect(QPoint(left, top), QPoint(right, bottom)));
        } else {   /////I've added the whole else
            updateCursorShape(e->globalPos());
        }
    } else {
        updateCursorShape(e->globalPos());
    }
}

void FrameLess::updateCursorShape(const QPoint &pos) {
    if (_parent->isFullScreen() || _parent->isMaximized()) {
        if (_cursorchanged) {
            _parent->unsetCursor();
        }
        return;
    }
    if (!_leftButtonPressed) {
        calculateCursorPosition(pos, _parent->frameGeometry(), _mouseMove);
        _cursorchanged = true;
        if (_mouseMove.testFlag(Edge::Top) || _mouseMove.testFlag(Edge::Bottom)) {
            _parent->setCursor(Qt::SizeVerCursor);
        } else if (_mouseMove.testFlag(Edge::Left) || _mouseMove.testFlag(Edge::Right)) {
            qDebug() << QDateTime::currentDateTime() << "FrameLess::updateCursorShape : _parent->setCursor(Qt::SizeHorCursor)";
            _parent->setCursor(Qt::SizeHorCursor);  //commenting out helps for the error
        } else if (_mouseMove.testFlag(Edge::TopLeft) || _mouseMove.testFlag(Edge::BottomRight)) {
            _parent->setCursor(Qt::SizeFDiagCursor);
        } else if (_mouseMove.testFlag(Edge::TopRight) || _mouseMove.testFlag(Edge::BottomLeft)) {
            _parent->setCursor(Qt::SizeBDiagCursor);
//        } else if (_cursorchanged) {
        } else {
            qDebug() << QDateTime::currentDateTime() << "FrameLess::updateCursorShape : _parent->unsetCursor()";
            _parent->unsetCursor();
            _cursorchanged = false;
        }
    }
}

void FrameLess::calculateCursorPosition(const QPoint &pos, const QRect &framerect, Edges &_edge) {
    bool onLeft = pos.x() >= framerect.x() - _borderWidth && pos.x() <= framerect.x() + _borderWidth &&
        pos.y() <= framerect.y() + framerect.height() - _borderWidth && pos.y() >= framerect.y() + _borderWidth;

    bool onRight = pos.x() >= framerect.x() + framerect.width() - _borderWidth && pos.x() <= framerect.x() + framerect.width() &&
        pos.y() >= framerect.y() + _borderWidth && pos.y() <= framerect.y() + framerect.height() - _borderWidth;

    bool onBottom = pos.x() >= framerect.x() + _borderWidth && pos.x() <= framerect.x() + framerect.width() - _borderWidth  &&
        pos.y() >= framerect.y() + framerect.height() - _borderWidth && pos.y() <= framerect.y() + framerect.height();

    bool onTop = pos.x() >= framerect.x() + _borderWidth && pos.x() <= framerect.x() + framerect.width() - _borderWidth &&
        pos.y() >= framerect.y() && pos.y() <= framerect.y() + _borderWidth;

    bool  onBottomLeft = pos.x() <= framerect.x() + _borderWidth && pos.x() >= framerect.x() &&
        pos.y() <= framerect.y() + framerect.height() && pos.y() >= framerect.y() + framerect.height() - _borderWidth;

    bool onBottomRight = pos.x() >= framerect.x() + framerect.width() - _borderWidth && pos.x() <= framerect.x() + framerect.width() &&
        pos.y() >= framerect.y() + framerect.height() - _borderWidth && pos.y() <= framerect.y() + framerect.height();

    bool onTopRight = pos.x() >= framerect.x() + framerect.width() - _borderWidth && pos.x() <= framerect.x() + framerect.width() &&
        pos.y() >= framerect.y() && pos.y() <= framerect.y() + _borderWidth;

    bool onTopLeft = pos.x() >= framerect.x() && pos.x() <= framerect.x() + _borderWidth &&
        pos.y() >= framerect.y() && pos.y() <= framerect.y() + _borderWidth;

    if (onLeft) {
        _edge = Left;
    } else if (onRight) {
        _edge = Right;
    } else if (onBottom) {
        _edge = Bottom;
    } else if (onTop) {
        _edge = Top;
    } else if (onBottomLeft) {
        _edge = BottomLeft;
    } else if (onBottomRight) {
        _edge = BottomRight;
    } else if (onTopRight) {
        _edge = TopRight;
    } else if (onTopLeft) {
        _edge = TopLeft;
    } else {
        _edge = None;
    }
}

void FrameLess::setBorderWidth(int borderWidth) {
    _borderWidth = borderWidth;
}

int FrameLess::borderWidth() const {
    return _borderWidth;
}

mrjj

@michalos said in Mouse cursor changes to 'resize' on inner widgets:

QEvent::Leave:

When you move away from the widget, QEvent::Leave should show its debug. ?
Else it wont be reset again. it seems.

michalos

@mrjj But the QEvent::Leave only happens when I leave the widget.
The error occurs on the child widgets, so I don't get the QEvent::Leave.
I don't get any debug info, when the error occurs.

mrjj

@michalos

When the cursor chances. is the _cursorchanged then true?

michalos

@mrjj Yes. The _cursorchanged = true and I get a QEvent::CursorChange.
Do you think it could be because of thin side borders?
I did a test and also added a debug message when any event occures. It's like once in two three tries the _cursorchanged variable is not switched to false

This is how the window looks like. I needet to do a photo with my phone, because with a standard print-screen the mouse cursor wasn't visible.
alt text

mrjj

@michalos said in Mouse cursor changes to 'resize' on inner widgets:

Do you think it could be because of thin side borders?

Well if it tries to detect the cursor leaving such small area, then yes.
Its very possible to skip a mouse pos now and then.
I made an app where i detected mouse moving out of app.
If i did it fast enough, sometimes it would not see it.

Can u test by making border much bigger?

michalos

@mrjj I've made the borders bigger and the problem stoped. So this seemst to be the source of the problem.
Fortunately I have only two child widgets, and both are custom, so I've just added a signal to their enterEvent() and connected the signal to a slot in the resizing class, that resets the mouse cursors shape.
Thank You so much for your help. I wouldn't have solved it on my own.

mrjj

@michalos
Heh well you actually did find it on your own :)
So good work :\o/

Solved Mouse cursor changes to 'resize' on inner widgets